It's the difference between someone who can maintain a comfortable lifestyle for the rest of their life if they don't go overboard, and someone who has enough money to start pursuing other ventures at cost. This comes with a whole lot of changes like losing most of your 'poor people' friend circle and rubbing shoulders with impactful people.

As the creator of Minecraft put it:

>Once I realized I had fuck-you money and didn't care about my public image any more because it didn't affect my day to day life in any way